For some time, known flush toilets configured to be flushed with flush water supplied by jet pump action so as to discharge waste have included, for example, the apparatus set forth in Patent Document 1 (Japanese Patent Unexamined Publication No. 2014-190065). In such apparatus, a portion or flush water supplied from a water supply source is stored, and a tank supplying flush water to the toilet main unit is installed on the top surface of the toilet main unit.
In recent years, with the increasing diversity of flush toilet design and greater water conservation, “low silhouette type” tanks have been employed, in which tanks are disposed at a relatively low position on the rear side of the toilet main unit so that the height position of the top edge of the tank can be set at a low position, minimizing the overall height of the flush toilet. In such low silhouette-type tanks, the connection between the tank and the toilet main unit may be made inside the tank if both a compact both front-to-back (depth) dimension and left-to-right (lateral) dimension are sought.
It is therefore possible to conceive of connecting the outlet of the tank and the inlet of the toilet main unit in a watertight manner from the interior of the tank, after first assembling the tank in a predetermined installation position relative to the toilet main unit. In such cases, if the center axis of the inlet of the toilet main unit and the center axis of the outlet of the tank are offset, the connecting pipe connecting the inlet of the toilet main unit and the outlet of the tank will be disposed at a diagonal, for example.
Hence when a tank is connected to a toilet main unit, the tank is disposed at a diagonal, resulting in the problem that the desired water level inside the tank cannot be attained, or the jet pump unit or related parts for inducing a jet pump action fail to operate correctly in response to the water level inside the tank.
As a result of the above, the flush water volume supplied to the toilet main unit from the tank is unstable, leading to the risk that flush performance will degrade, or water conservation performance will drop.